This invention relates to repertory dialers, and more particularly to microprocessor controlled repertory dialers including a storage facility for data associated with stored telephone numbers to be automatically dialed upon command, wherein a telephone number field is encoded in a first code, and data stored in a field for associated-data is encoded in a second code.
Prior art devices for storing telephone numbers and names associated therewith, according to an alphabetic hierarchy of the names, are disclosed in Hagelberger et al U.S. Pat. No. 3,242,470. Similarly, Fujimura U.S. Pat. No. 4,104,717 provides a telephone information retrieval system in which each entry includes name, address and other information, while Roberts No. 4,118,788 discloses associated retrieval data, such as a telephone directory listing of numbers, along with names, addresses and the like.
Auto-dialing circuits are known as described at Hestad et al U.S. Pat. No. 4,232,200, and Lake et al U.S. Pat. No. 4,178,487.
However, none of the prior art discloses a combination in which a telephone number is stored along with associated search data, in which the search data may be displayed and the telephone number automatically dialed at the option of an operator.
Particularly, none of the known prior art provides efficient storage of variable length fields of telephone numbers and associated data in which terminating characters are not required between the fields.
It is accordingly a primary object of the present invention to provide a microprocessor controlled repertory dialer having efficient data storage, and a method for operating such a dialer.
It is a more specific object of the invention to provide a repertory dialer in which variable length fields of telephone numbers and associated data are provided, without requiring the use of separating or terminating characters between such fields.
Still a further object of the invention is the provision of a repertory dialer in which a multichip microprocessor is utilized in order efficiently to store data, to access and search such data, to display the data and to dial a telephone number for accessing that telephone circuit.
Still another object of the invention is the provision of a power supply for a repertory dialer, in which a backup battery is provided along with charging means therefor, and circuitry for connecting the battery to the dialer when the primary source of power fails.
Yet a further object of the invention is the provision of a repertory dialer having memory safety circuits for disabling alteration of data stored in the memory upon failure of externally supplied voltage thereto.